Which describes a constant in an experiment?
a. the variable changed by the experimenter
b. the quantity that must remain the same
c. the variable that changes in response to the experiment
d. the statement that is worded to test the experiment

B Constant is a situation or state of affairs that does not change

This is what i found on google “phytoplankton, tiny organisms that live in the ocean, are autotrophs. some types of bacteria are autotrophs. most autotrophs use a process called photosynthesis to make their food.” i hope this you for what your looking for